System/Path: Add x86-64 COFF to IdentifyFileType.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114037 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Path.cpp b/lib/System/Path.cpp
index 0026fd2..ae166a5 100644
--- a/lib/System/Path.cpp
+++ b/lib/System/Path.cpp
@@ -127,6 +127,10 @@
       if (magic[1] == 0x02)
         return COFF_FileType;
       break;
+    case 0x64: // x86-64 Windows.
+      if (magic[1] == char(0x86))
+        return COFF_FileType;
+      break;
 
     default:
       break;